Harrow



' S (No Model.) i

' 0. LA DOW.

HARROW.

I Patented July 18, 1893.

lllllllll llllllllll li rllmlll 9 m 2 j w A znessesi A Inn/anion UNITEDSTATES PATENT OFFICE.

CHARLES LA Dow, or ALBANY, NEW YORK.

HARROW.

SPECIFICATION forming part of Letters Patent No. 501,886, dated July 18,1893.

Application filed September 8, 1891. Serial No. 405,089- (No model.)

T0 aZZ whom it may concern:

Be it known that I, CHARLES LA DOW, a citizen of the United States,residing at Albany, in the county of Albany and State of New York, haveinvented certain new and useful Improvements in Harrows, of which thefollowing is a specification.

My invention relates particularly to that class of harrows in whichspring teeth are employed to stir the soil, but my improvements areapplicable to machines of different kinds and employed for otherpurposes.

In applying my invention to a spring tooth harrow, I preferably employcurved teeth of the Garver type mounted on a rigid frame provided with aseries of tooth-bearing portions, each of which carries a single tooth,and the frame bars radiate from the toothbearing portions to brace thesupports of the teeth.

In this class of harrows, in order to vary the pitch or depth of out ofthe teeth, it has heretofore been necessary to loosen the bolts whichclamp the teeth and frame together, and to adjust each tooth separately.This operation requires considerable time, and involves the use oftools. It is also difficult to set all the teeth to work uniformly andpenetrate the soil to the same extent.

The primary object of my invention is to provide means for adjusting theteeth to vary their pitch, or the position 'of their points, withoutloosening their attachment to the frame. Harrows have, of course, beenprovided with means for adjusting the pitch of all the teeth, but, sofar as I am aware, no

- means have been heretofore provided for adjusting the teeth withoutthe use of hinges, or without unfastening the teeth relatively to theirframe. In my Patent No. 494,538, of

March 28, 1893, I have shown and described a spring tooth harrow ofthe'modern type, and have claimed broadly means for adjusting the teethin this class of harrows. In that case the teeth were adjusted by movingone part of the frame relatively to the other, two duplicate framesbeing employed, connected by links and adj ustedby lever mechanism. Inthe present case, the frame'and teeth are secured together rigidly, andin order to adjust the teeth to vary their pitch or depth of cut,

I do not move the frame, or any part thereof, or move the teethrelatively to the frame, but provide means for adjusting the teeth byspringing them from one position to another, the teeth being held undertension in one position, and when this tension ,is released by their ownresiliency, moved to another.

In the accompanying drawings, illustrating one way of carrying out myinvention, Figure 1 is a plan view of a complete spring tooth harrow ofthe modern type, with my improvements applied. Fig. 2 is a sideelevation thereof. Fig. 3 is a detail view on an enlarged scale,showing'the manner of connecting a tooth to the frame. Fig. 4 is adetail view of adjusting mechanism, which may be employed. Figs. 5 and 6are views of one of the brackets forming part of the tooth-adjustingmechanism. Figs. 7, 8 and 9 are detail views of teeth having modifiedconstructions.

The frame shown in the drawings is of the same general construction asthat shown in my Patent No. 455,260, of June 30, 1891, and is of ageneral butterfly, A, or heart-shape. The frame bars A A are arrangeddiagonally across the line of draft, and the teeth a, are arranged indiagonal series in order that they may more readily dropweeds andrubbish, as the implement proceeds.

As shown, the frame is made in two sec tions hinged together'at H, andeach section has a series of tooth-bearing portions, steps or offsets0c,'each of which carries a single tooth. The ofisets of the bars A,overlap those of the bars A, and the shanks of the teeth are clampedbetween the ofisets of dif- 4 ferent bars and held bybolts 0c. The arrangement is such that each tooth-bearing portion of the frame is bracedby the frame bars which radiate in different directions from it, andeach tooth, (except those at the rear of the machine,) works in its ownindividual opening in the frame, which is substantially diamond-shaped.The utility of this arrangement is that when the teeth are adjusted inthe manner hereinafter explained, they are more effectively freed fromweeds, rubbish,

&c., by the frame bars, each tooth being inclos'ed'by frame bars andthus separated from all the others. Weeds will not get tangled upbetween two or more teeth, as would be the-case if a plurality of teethwere arranged in close proximity and worked in the same openings.

Of course I am aware that it is common to arrange the teeth and frame inthis general way. Numerous patents heretofore granted show it; but thisarrangement is especially advantageous when devices are employedforsimultaneously adjusting all the teeth to clear them of rubbish. Thisfeature is claimed more broadly in my application above mentioned, butit is alsoclaimed in connection with my present improvements. In thepresent case, the teeth are held down to their work under tension, andby simultaneously releasing the tension of all the teeth, theysimultaneously spring up either above the frame to clear themselves ofweeds, rubbish, &c., or simply rise to the desired extent to vary thepitch or positions of their points, according as they are controlled bytheir lever-governing devices. y

In Fig. 3, the tooth a, is shown as provided with a curved springportion or shank a, which is more resilient than the body of the tooth.As here shown, the shank a, is made thinner than the body A, andsomewhat wider. This may be accomplished without loss of any of thestock, and maintains the strength of the tooth,while providing thedesired difference in resiliency. The same result may be accomplished asshown in Fig. 7, by providing a supplemental spring shank; or, as shownin Figs. 8 and 9, by stiffening the main body portion of the tooth at M,cutting away or reducing the width of the pointp, and likewise that ofthe curve shank c. Other ways might be suggested. I The ends of theshanks are clamped between the-overlappin g offsets of theframe bars bybolts 00, but obviously, other ways might be employed for rigidlyconnecting the teeth to the frame. This way, however, affords convenientmeans for individually adjusting each tooth, it being understood thatwhen the teeth are once adjusted in the frame it is not often that theyrequire individual adjustment, as, by my improvements, the teeth are allsimultaneously adjusted to vary their pitch or depth of cut.

At each tooth-bearing portion of the frame, is mounted a bracket B,having bearing lugs 11, for rock bars or rods'c', forming part of thetooth-adjusting mechanism. I have shown three such rods on each side ofthe frame; they are preferably square in cross section and extendthrough square perforations in the levers Z Z. The rock bars arearranged diagonally in the same general direction as the bars A, andextend through the perforations in the lugs Z2, being free to rocktherein. The rock bars 2', carry a series of eccentrics C, one for eachharrow tooth. These eccentrics are rigidly secured to the rock bars andengage with links c, connected to the teeth at a between their bodyportions and their resilient shanks. Each link restsin a groove 0', inthe eccentric, so that it is held in proper working position. The teethare so connected to the frame and to the eccentrics, that when free,they occupy the position shown in Fig. 3 with their'points above theframe bars, the resiliency of the teeth holding them in this position;and, by turning the eccentrics by means of the rock bars, the points ofthe teeth may be lowered, as indicated by dotted lines in Fig. 3, andheld against the force of the spring shanks in working position. I donot limit myself to this particular method of springing the teeth.

It is obvious that the position of the teeth may .be adjusted to anydesired extent, by a corresponding movement of the eccentrics,

and that when the eccentrics are moved suddenly from the position whichthey occupy in holding the teeth down to their work, the teeth willsimultaneously and instantaneously spring up above the frame and shakeoff and clear themselves from weeds, rubbish, &c.

In Fig. 1, I have shown each section of the frame, as provided with aseries of levers Z, Z, connected by links n, which are self-locking, buta single lever may be connected with all the rock shafts to adjust allthe teeth simultaneously in both sections of the frame. Instead ofemploying levers with lock joints, I may employ a lover, or levers,provided with detent mechanism engaging a toothed segment 1', as shownin Fig. 4, but any other device may be employed for simultaneouslyreleasing the spring-controlled teeth, or putting them under tension,and holding them. The levers shown in Figs. 1 and 2 are so arranged thatthey may be folded down among the harrow teeth, so as not to projectabove them, and the rock bars are so arranged that they do not interferewith the proper working of the teeth nor prevent them from clearingthemselves effectively.

While I have described my invention as applied to a spring-tooth harrowhaving a frame of the modern type and provided with teeth of the Garvertype, I wish it understood that I do not limit myself to this kind ofteeth, nor to this kind of frame. The frame may be of wood or metal andof any form, and the teeth may be operated by other mechanism than thatherein shown. The teeth may be either resilient in themselves, or beattached to other springs, or provided with other means for holding themunder tension. 5 v

I have shown and described the best way now known to me of carrying outmy invention, and, while I claim the special organization shown, and thedetails of construction, I wish it understood that my invention isbroader and more far reaching; for, so far as I am aware, I am the firstto make a machine whose teeth can be adjusted as to pitch without movingthe support on which they are mounted, and without interfering with therigid connection between the ends of the teeth and the frame; or, inwhich harrow teeth are provided with meansfor holding the points IIO ofthe teeth to their work under tension and with devices for releasingthis tension to adjust the position of the points, or to cause the teethto spring above the frame to clear themselves of rubbish.

lVhat I claim is V 1. The combination of'a-harrow frame, and a series ofyielding teeth rigidly secured to stationary portions of the frame, andlever tactwith the ground when. in a normal -posi-.

tion by spring tension, in combination with means adapted to spring theteeth so that their points shall enter the ground and be held underspring tension.

4. In a harrow, a draft frame,-and,spring teeth supported thereon, incombinationwith means adapted to hold the teeth to their work undertension and to release them from press-. ure to permit them to assume aposition with.

their pointsabove the frame by their own recoil. V

5. In a barrow, a draft frame and spring teeth rigidly secured thereto,yielding connections between the working portions of the teeth andtheframe, and means for holding the teeth under tension in differentpositions and for allowing them to quickly assume another position bymeans of their ownvolition or resiliency when the tension is removed.

6. In a harrow, a frame provided. with a series of tooth-bearingportions, a series of spring teeth mounted thereon, and a device betweentheir points and their fastened por tions.

having a. series of tooth-bearing portions, a series of spring teethmounted thereon, a rock tween the eccentrics and, the teeth for varyingthe elevation of the working ends of the teeth. r

V Intestimony, whereof I have hereunto subscribed my name.

Witnesses:

LLOYD B. WIGHT,

B. WASHINGTON MILLER.

7.;In-a harrow,the combination of a frame.

shaft carrying eccentrics and connections be- CHARLES LA Dow.

connected with the-teeth for bending them

